from manim import *
class math(MovingCameraScene):
    def construct(self):
        self.camera.background_color = BLACK  # 设置背景颜色
        self.camera.frame_width = 100  # 设置边框宽度
        self.camera.frame_height = 60  # 设置边框高度
        self.camera.pixel_height = 1080  # 设置像素高度
        self.camera.pixel_width = 1920  # 设置像素宽度
        self.camera.center = ORIGIN  # 设置中心点位置
        self.camera.scale_factor = 1.0  # 设置缩放因子
        #设置横线
        for i in range(60*2+1):       
            dot1=Dot([-500,5*(i-60),0]).set_opacity(0.5)
            dot2=Dot([500,5*(i-60),0]).set_opacity(0.5)
            if i==6:
                line1=Line(dot1,dot2).set_color(WHITE).set_opacity(0.5)
                
            else:
                line1=Line(dot1,dot2).set_color(WHITE).set_opacity(0.5)
               
            self.add(dot1,dot2,line1)
        #设置竖线
        for i in range(100*2+1):        
            dot3=Dot([(i-100)*5,-300,0]).set_opacity(0.5)
            dot4=Dot([(i-100)*5,300,0]).set_opacity(0.5)
            if i==10:
                line2=Line(dot3,dot4).set_color(WHITE).set_opacity(0.5)
                
            else:
                line2=Line(dot3,dot4).set_color(WHITE).set_opacity(0.5)
            self.add(dot3,dot4,line2)
        #设置三个点
        dot1 = Dot(radius=1, color=RED)  
        dot1.move_to([-47.5,27.5,0]) 
        dot2 = Dot(radius=1, color=YELLOW)  
        dot2.move_to([-42.5,27.5,0])  
        dot3 = Dot(radius=1, color=GREEN)  
        dot3.move_to([-37.5,27.5,0])
        #镜头跟进效果 
        self.camera.frame.save_state()
        #题目出现
        text = Tex(
                r"\text{计算}\hspace{0.3em}$\int_{0}^{+\infty} \dfrac{x \ln x}{1 + x^4} \, dx$",  # 0.3em 可自由调整
                tex_template=TexTemplateLibrary.ctex
                    ).scale(5.0).move_to([0, 0, 0])
        
        self.play(Write(text),self.camera.frame.animate.scale(0.8))
        self.wait()
        #镜头拉回
          #分析文本
        #text100=MarkupText("<b><i>分析/解：</i></b>",color=PINK).scale(5.0).move_to([-38,12.5,0])
        self.play(Restore(self.camera.frame))
        self.play(FadeIn(dot1),run_time=0.1)
        self.play(FadeIn(dot2),run_time=0.1)
        self.play(FadeIn(dot3),run_time=0.1)
        #题目向上移动
        self.play(text.animate().move_to([0,20,0]) )
        #镜头拉近
        self.play(self.camera.frame.animate.scale(0.8).move_to([0,5,0]))

        
        #框框标
        rectangle=Rectangle(color=BLUE,fill_opacity=0.3,width=17,height=8
                            ,stroke_color=BLUE,stroke_width=20)
        rectangle.move_to([3, 20, 0])
        long_text=("两个特征")
        text100 = Text(long_text,color=YELLOW,
                   font_size=200).next_to(rectangle,DOWN,buff=1)
        long_text1=("两种思路")
        text101 = Text(long_text1,color=YELLOW,
                   font_size=200).next_to(rectangle,DOWN,buff=1)
        #框框标
        
        self.play(Create(rectangle),Create(text100))

        self.play(ReplacementTransform(text100,text101))
        self.wait(0.2)
        

        long_text2=("思路一：")
        text102 = Text(long_text2,color=YELLOW,
                   font_size=200).move_to([-30, 10, 0])
        self.play(ReplacementTransform(text101,text102),Restore(self.camera.frame))
        self.wait(0.2)
        #框框标

        
        long_text3=("特征：分子分母阶差较大")
        text103 = Text(long_text3,color=YELLOW,
                   font_size=200).next_to(rectangle,DOWN,buff=1)
        long_text4=("倒代换")
        text104 = Text(long_text4,color=YELLOW,
                   font_size=200).next_to(rectangle,DOWN,buff=1)
        
        
        text1 = Tex(
                r"\text{令}$x=\dfrac{1}{t}$",color=YELLOW,  # 0.3em 可自由调整
                tex_template=TexTemplateLibrary.ctex
                    ).scale(5.0).next_to(rectangle,DOWN,buff=1)
        
        #框框标
        self.play(Create(rectangle),Create(text103))
        self.play(ReplacementTransform(text103,text104))
        self.wait(0.2)
        self.play(ReplacementTransform(text104,text1))
        self.wait(0.2)
        text2 = Tex(
                r"$\int _{+\infty }^{0}\dfrac{\dfrac{1}{t}\ln \dfrac{1}{t}}{1+\dfrac{1}{t^{4}}}\cdot \dfrac{-1}{t^{2}}dt$",color=WHITE,  # 0.3em 可自由调整
                tex_template=TexTemplateLibrary.ctex
                    ).scale(5.0).move_to([0, 0, 0])
        self.play(Write(text2))
        text3 = Tex(
                r"$-\int _{0}^{+\infty }\dfrac{t\ln t}{t^{4}+1}dt$",color=WHITE,  # 0.3em 可自由调整
                tex_template=TexTemplateLibrary.ctex
                    ).scale(5.0).move_to([0, 0, 0])
        self.play(ReplacementTransform(text2,text3))
        self.wait(0.2)
        text4 = Tex(
                r"$\int _{0}^{+\infty }\dfrac{x\ln x}{x^{4}+1}dx=-\int _{0}^{+\infty }\dfrac{t\ln t}{t^{4}+1}dt$",color=WHITE,  # 0.3em 可自由调整
                tex_template=TexTemplateLibrary.ctex
                    ).scale(5.0).move_to([0, 0, 0])
        self.play(ReplacementTransform(text3,text4),ReplacementTransform(rectangle,text4))
        self.wait(0.2)
        text5 = Tex(
                r"$\int _{0}^{+\infty }\dfrac{x\ln x}{x^{4}+1}dx=-\int _{0}^{+\infty }\dfrac{x\ln x}{x^{4}+1}dx$",color=WHITE,  # 0.3em 可自由调整
                tex_template=TexTemplateLibrary.ctex
                    ).scale(5.0).move_to([0, 0, 0])
        self.play(ReplacementTransform(text4,text5))
        self.wait(0.2)
        text6 = Tex(
                r"$2\int _{0}^{+\infty }\dfrac{x\ln x}{x^{4}+1}dx=0$",color=WHITE,  # 0.3em 可自由调整
                tex_template=TexTemplateLibrary.ctex
                    ).scale(5.0).move_to([0, -10, 0])
        self.play(Write(text6))
        self.wait(0.2)
        #框框标
        rectangle=Rectangle(color=BLUE,fill_opacity=0.3,width=17,height=8
                            ,stroke_color=BLUE,stroke_width=20)
        rectangle.move_to([3, 20, 0])
        text7 = Tex(
                r"$=0$",color=YELLOW,  # 0.3em 可自由调整
                tex_template=TexTemplateLibrary.ctex
                    ).scale(5.0).next_to(rectangle,RIGHT,buff=1)
        self.play(Create(rectangle),ReplacementTransform(text6,text7))

        self.wait()